Automatic electric water-heater.



J. I. AYER. AUTOMATIC ELECTRIC WATER HEATER.

APPLICATION FILED JAN. 2T 1912.

Patented June 11, 1912.

UNrrEn STATES PATENT OFFICE.

JAMES I. AYER, OF CAMBRIDGE, MASSACHSETTS, ASSIGNOR TO SIMPLEX ELECTRIC,

HEATING COMPANY, OF CAMBRIDGE, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS.

AUTOMATIC ELECTRIC WATER-HEATER.

Specification of Letters Patent. Patented J une 11, 1912.

Application filed January 2, 1912. Serial No. 669,067. i

To all whom it may concern:

Be it known that I, JAMES I. AYER, a citizen of the United States, and resident of Cambridge, county of Middlesex, and State of Massachusetts, have Vinvented an Improvement in Automatic Electric Vater- Heaters, of which the following description,

in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

This invention relates to elect-ric water ropening the heating circuit when the water has reached a predetermined temperature, and closing the same when its temperature falls below this point.

rlhe water-containing vessel is preferably inclosed with an insulating jacket, so that radiation is reduced to a minimum, and thus only a very small current supply is required to make up for the slight heat losses which occur through radiation and keep the water in the vessel hot.

The invent-ion will be better understood from the following detailed description,

taken in connection with the accompanying drawings, and will be thereafter pointed out-.in the appended claims. :Referring to the drawings: The figure shown is a central vertical section through thedevice, certain of the parts being shown in elevationj, y

The vessel-10 may be of any desired form in cross section and in the preferred arrangement shown is adapted to st-and upright. It has a removable base plate 11, and

spaced apart fromsaid plate a removable bottom plate 12 for the water containing chamber, th'isbottom plate being shown as in threaded engagement with the interior of the vessel, as seen at 13, and having upstanding therefrom a central tubular housing lflextending up through the body of the vessel and closed at its upper end. An electric resistance element 15 of any suitable form is mounted within this housing,

this element being shown as an ordinary resistance wire or ribbon wound on a tubular sleeve 16 and embedded in enamel 17, or

the like. One of the terminal conductors 18 connects directl with this resistance ele'- ment, and the other conductor 1 9 is connected to the other end of said resistance element through a thermostat 20, shown with a condenser 21 connected in multipley therewith. The t-hermostat 20, which typies any suitable circuit controlling. device operable by the thermal condition of the interior of the vessel, is shown as formed of two strips of metal having dissimilar expansion coefficients, so that when fixed together as a compound plate it will bend under the influence of heat, and'break the circuit connection from its outer end to a' contact pin 22, which is in connection with the resistance element and with the condenser'by a connection 23, the conductor 19, having connection with the other end of this compound plate andwith the condenser,

as seen at 24. l

The water inlet pipe 25 opens into the lower part of the containing vessel as seen at 26, and is controlled by a suitable valve 27. The water delivery pipe 28 isy shown as extending up to near the top of the containing vessel at 29, as an overow pipe, the water deliveryv being controlled from the valve 27 in the inlet, so that'the discharge pipe takes water from the top of the heater and in ope-ration, as the cold water expands on heating, the accumulation of pressure in l thfv'essei is avoided. The entire `vessel is preferablyy covered with an insulating Jacket 30, an external casingbeingusually'fitted'y over this insulating jacket in practice. asa .5 vprotection therefor. The thermostat, being thus housedfin the V'base of the vessel and in proximity'to the heater and to the water contents, is adapted for adjustment so as tolbreak the circuit whenever the water 1g reaches any particular desiredtemperaturei from the boiling point downward; as a convenient means for adjusting theI pointv at which breaking of the circuit will take place, the contact pin 22 may be formed as an adjusting screw threaded through a post .31, as shown.

While the association of the condenser.

with the thermostat control is\advantageo us and1desirable, it will be understood that 20 many cases a condenser -is not necessary, thecurrent supply often being such that a thermostat-will o eratesatisfactorily, without a conde'nser for reducing the spark.' The heat' vice as shown is provided with only a single i heater, it is quite practicable to provide a series of heatersaand a series of thermostats with or without condensers, Where more heat and a larger hot water delivery is required, for which the necessary amount of current could not conveniently be controlled'with a 4.0v single thermostat.

l While inthe particular embodiment of the invention shown, the several parts constructedas set forth, cooperate in an eiiicient l"and especially advantageous manner, it is to be understood that various of the details may be modiedand the relative arrangements 4of parts changed without departing from'the spiritof the invention. For example, the invention in its broader aspects is not limited to any special form of circuit Y control, so long as it is effected by the thermal condition of the vessel and its contents, and the particular location of the thermostat or the thermostat and condenser in the, base and with the base formed as shown, is

immaterial to the f generic combinations which I desireto protect. I therefore do not desire to be limited inithese particulars,or in an'y others, except as set '/forth in the apl pended claims.

Having' described my invention, what I vclaim -as new and desire to secure by Letters Patent is:

1. A device of the kind described, coml 55 prising a vesselhaving liquid supply and Localiza I deliveryconnections, means for dividin oif l a portion of sald vessel to form a lower ase portion' and' `ai1"upper liquid lholding body portion, an electric heater mounted in saidv i' ody portion, and a thermostat in said base' 70 portion, said'thermostat being formed and' connected Ato render said heater inoperative at a predetermined thermal condition of the vessel contents.- Y 2. A 'device of the kind described, com-,75 prising a vessel having liquid supply and delivery connections and formed with a removable'bottom, a removable plate adapted to lbe fitted within said vessel to divide oil" the lower from the upper part thereof, an 30 electric heater ttedwithin said vessel, Aand a thermostat mountedin said lower part of said vessel connected to'control saidheate'r by the thermal condition of the interior of the vessel. A

. 3. A device of the kind described, compris- :I` ing a vessel having liqnidsupply and deliv-` ery connections,one end .thereof being'reesv 'movable, a removable partition'dividing o t said vessel to' form aliquid holding body .9@ portion and an end portion separated therefrom, an electric heater mounted in said bodyportion of the vessel, and current controllingmeans 'mounted -in said endportion of the vessel connected to control said heater I and operable by the Ithermal conditionof the vessel contents.

4. A device of the kind described, comprising a vessel h'aving liquid supply and 'f delivery connections, a removable plate itted in said 'vessel for dividing oli the same to-form a liquid holding body portion and an end portion separated therefrom, said plate carrying a housing projecting into the body portion of the vessel, an electricheater fitted in said housing, and current controlling means forsaidheater mounted in said end portion of the vessel', saidmeans being operable by the thermal condition of the vessel contents.

.5. A device of the kind described, comprising a vessel having liquid supply and delivery connections, means for dividing oil' said ,vessel to form -a liquid holding body portion and a base portion vwith a housing extending into the body portion, an electric heater fitted 4in said housing, and a thermostat with a condenser connected thereto mounted'in said'base portion, said thermostat being arranged and connected to con-l trol said heater and being operable by the thermal condition of the vessel contents.

6. A device of the kind described, comprising an inc'losed vessel, means for divid ing said vessel to form a lower base portion and an upper liquid holding body portion,v

a valve controlledinlt to the lower part of .v

said body portion, an voutlet connection from l the upper part of said body portion, a housing extending into said body portion, an

memes eectre heater in said housing, and e, "bhefname co this speecadten, iig "he presence ef mostat Wlth'a condenser attachment m sind two subsembmg wlnesses., 1

base, said thermostat being connected to T S I YER @pen the circuit to said heater, as the Vessel d L and its contents reach a prede'ermned temnWitnesses: perature. C. JJLLAvfs,

1n testmofny whereof, have signed my LLIZABETH M. CONLN.` 

